This invention relates generally to a connector for coupling to the end portion of a helically corrugated conduit such as a coaxial conductor.
Connectors have existed in the past for coupling to a helically corrugated conduit. For instance, U.S. Pat. No. 4,824,401 (Spinner) taught the use of a plastic ring which is placed around the corrugated outer conductor between a coupling ring and a metal casing where the coupling ring is engagable to the metal casing. The plastic ring is positioned with one end face against a radial annular surface of the coupling ring and with its opposing end face against a radial annular surface of the metal casing. The plastic ring is then compressed when the coupling ring is threadingly tightened to the metal casing thereby resulting in the plastic ring being forced inwardly against the corrugated outer conductor. The above and other similar assemblies which provide a radial force to the associated conduit have the disadvantage that the radial force applied to the conduit tends to result in damage to the conduit.
Another connector for coupling to a helically corrugated conduit, disclosed in U.S. Pat. No. 3,757,583 (Staschewski), provides an external flange or collar which extends radially from along a crest line of the corrugations of the conduit. The flange is placed into abutment with a helically configured internal flange or collar of a coupling element by screwing such element onto the end of the conduit. The coupling element is then secured to a connector by a bolt or clamp.
Still another connector for coupling to a helically corrugated conduit is U.S. Pat. No. 4,687,272 (Spinner et al.). Spinner et al. discloses a flanged end section of a helically corrugated outer conductor against which a corrugated pipe nut abuts. A screw cap which is positioned around a portion of the helical conductor is then threadingly engaged to a connector. The screw cap cooperates with the corrugated pipe nut in such a manner that upon turning the screw cap along the connector, the nut is forced against the flanged end section of the conduit thus securing the flanged end section between the nut and an internal flange of the connector.
The above and other similar prior art connectors for coupling to a helically a corrugated conduit require a flange or collar be located either along the crest line of the helical corrugations of the conduit or at the end of the helically corrugated conduit. This requirement adds to the production cost of the helically corrugated conduit. Further, if the flange or collar is located only on the end of the conduit, additional effort and tools are required to alter the length of the conduit in the field.